KR101151377B1 - hydraulic cylinder internal mounting check valve - Google Patents

Abstract

The present invention provides a cushion-integrated hydraulic cylinder with a built-in cushion device (referring to a cushion ring and a cushion plunger) to reduce the mechanical shock generated at the stroke end, the hydraulic cylinder of the hydraulic cylinder at the beginning of the movement after the change of direction at the stroke end. It is to improve the efficiency of the hydraulic pump by improving the operation delay and initial sudden phenomenon,

Hydraulic cylinder in which the check valve according to an embodiment of the present invention is built,

A cylindrical cylinder tube with an empty interior,

Piston for maintaining the water pressure by partitioning the large chamber and the small chamber inside the cylinder tube,

A cylinder rod for linearly reciprocating the piston in the cylinder tube,

A head cover and an end cover fixed at both ends to prevent leakage of hydraulic oil from the cylinder tube;

Cushioning and cushioning plungers respectively mounted on the outer side and one end of the cylinder rod to absorb mechanical impact at the stroke end;

A flow path formed in the head cover to communicate with the hydraulic oil port of the head cover;

Including a check valve installed to open and close the flow path,

The piston is closed by the hydraulic oil supplied through the first thrust which pressurizes the cushioning during the initial movement after the change of direction at the stroke end and the operating oil supplied through the passage which is opened during the initial movement after the change of direction at the stroke end. A second thrust under pressure can be secured.

Hydraulic cylinder, check valve, cushioning device, thrust, stroke end, head cover

Description

Hydraulic cylinder with built-in check valve

The present invention is a cushion built-in hydraulic cylinder in which a cushion device (referring to a cushion ring and a cushion plunger) is built so as to reduce the mechanical shock generated at the stroke end, a check valve function is provided inside the hydraulic cylinder to move the piston. It relates to a hydraulic cylinder with a built-in check valve to ensure a sufficient thrust.

More particularly, the present invention relates to a hydraulic cylinder having a built-in check valve for improving a hydraulic cylinder's operation delay and initial sudden operation in the initial stage of movement after the change of direction at the stroke end. .

Hydraulic cylinder according to the prior art shown in Figure 1 (a, b, c),

A cylindrical cylinder tube (1) having an empty interior,

A piston (2) for dividing a large chamber and a small chamber inside the cylinder tube 1 to maintain water pressure;

A cylinder rod (3) for linearly reciprocating the piston (2) in the cylinder tube (1),

A head cover 4 and an end cover 4a (end cover) fixed to both ends to prevent leakage of hydraulic oil from the cylinder tube 1,

A cushion plunger fixed to one end of the cylinder ring 3 and a cushion ring 5 mounted on the outer side of the cylinder rod 3 so as to absorb mechanical shock at the stroke end. (6) (cushion plunger).

In the case of the cushion-integrated hydraulic cylinder configured as described above, a cushioning device (referring to a cushioning ring and a cushion plunger) is configured to reduce mechanical impact at the stroke end. In other words, by adjusting the opening area of the exiting flow path using a ring type or plunger type or the like and gradually throttling the flow path, the speed of the piston 2 is reduced to reduce the impact force. It is configured to

As shown in Fig. 1 (c), when the entry of the cushion device (referring to the cushion ring) to the stroke end is almost completed, the gap is kept in a minimized state for sufficient cushioning, and the end of the cushion device The mutual contact surfaces form a solid surface contact with each other.

On the other hand, when the cushion device comes out of the stroke end, an additional frictional force is formed and hydraulic oil is transferred from the hydraulic pump to the inside of the flow path. In practice, however, the cross-sectional area for conveying the cylinder rod 3 is formed only by the annular projecting area of the cushioning ring 5, which is very narrow (indicated by " a " in Fig. 1 (c)). This causes a time delay until pressure builds up to transport the cylinder rod 3 and a sufficient thrust is formed.

As shown in FIG. 2, when checking the problem from the hydraulic system point of view, when the hydraulic cylinder is first operated at the stroke end, the pressure of the discharge side of the hydraulic pump is increased due to the operation delay due to the lack of the hydraulic pressure area inside the hydraulic cylinder ( As indicated by the graph curve “b” in FIG. 2). This leads to reaching the relief pressure, causing unnecessary energy consumption. At this time, the graph curves "a" and "c" are curves representing pilot signal pressures supplied to the hydraulic pump regulator, respectively.

On the other hand, in terms of the operability of the hydraulic cylinder, it causes a phenomenon such as instantaneous initial sudden operation after the delay at the same time as the operation delay, it has a fatal factor in performance when required to precise work of the work device.

In addition, due to unnecessary energy consumption, fuel economy of construction equipment is deteriorated, and the hydraulic system has a system over design element such as an increase in the hydraulic pump capacity in order to provide smooth initial operability. There is a problem.

Embodiment of the present invention, in the built-in cushion hydraulic cylinder, the hydraulic pressure is built in the check valve to prevent the excessive pressure rise of the hydraulic pump according to the delay of the operation of the cylinder rod at the stroke end to improve the efficiency of the hydraulic pump Is associated with a cylinder.

The embodiment of the present invention, in the cushion-integrated hydraulic cylinder to prevent the excessive operation of the hydraulic pump at the stroke end, the initial operation of the hydraulic cylinder is ensured to improve the overall fuel efficiency (fuel efficiency) to reduce the cost cost It is associated with a hydraulic cylinder with a built-in check valve.

Hydraulic cylinder in which the check valve according to an embodiment of the present invention is built,

A cylindrical cylinder tube with an empty interior,

Piston for maintaining the water pressure by partitioning the large chamber and the small chamber inside the cylinder tube,

A cylinder rod for linearly reciprocating the piston in the cylinder tube,

A head cover and an end cover fixed at both ends to prevent leakage of hydraulic oil from the cylinder tube;

Cushioning and cushioning plungers respectively mounted on the outer side and one end of the cylinder rod to absorb mechanical impact at the stroke end;

A flow path formed in the head cover to communicate with the hydraulic oil port of the head cover;

Including a check valve installed to open and close the flow path,

The piston is closed by the hydraulic oil supplied through the first thrust which pressurizes the cushioning during the initial movement after the change of direction at the stroke end and the operating oil supplied through the passage which is opened during the initial movement after the change of direction at the stroke end. The second thrust to pressurize can be ensured.

According to a preferred embodiment, the above-described check valve,

A seating portion extending from one end of the flow path and installed with a check valve;

A body having a through hole coupled to the seating portion and communicating with the flow path;

Check ball to open and close the through hole,

A pusher for pressing and supporting the check ball,

An elastic member that biases the pusher to close the through-hole by the check ball to an elastic bias in an initial state;

It includes a plug screwed to the seating portion to support the elastic member.

The hydraulic cylinder with the built-in check valve according to the embodiment of the present invention configured as described above has the following advantages.

In the cushion-integrated hydraulic cylinder, it is possible to prevent the initial sudden operation of the hydraulic cylinder at the stroke end and to prevent excessive pressure rise of the hydraulic pump due to the operation delay, thereby improving the efficiency of the hydraulic pump.

In addition, in the built-in cushion hydraulic cylinder, it is possible to prevent excessive operation of the hydraulic pump by securing a hydraulic pressure area to pressurize the piston at the stroke end, it is possible to improve the overall fuel efficiency because the smooth initial operation of the hydraulic cylinder is secured.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to explain in detail enough to enable those skilled in the art to easily carry out the invention, and thus It is not intended that the technical spirit and scope of the invention be limited.

The hydraulic cylinder is built in the check valve according to an embodiment of the present invention shown in Figure 3,

A cylindrical cylinder tube (1) having an empty interior,

A piston (2) for partitioning the large chamber and the small chamber in the cylinder tube (1) to maintain the water pressure,

A cylinder rod (3) for linearly reciprocating the piston in the cylinder tube (1),

A head cover 4 and an end cover 4a fixed to both ends to prevent leakage of hydraulic oil from the cylinder tube 1,

A cushion ring (5) and a cushion plunger (6) mounted to the outer side and one end of the cylinder rod (3) so as to absorb a mechanical shock at the stroke end,

A flow path 7 formed in the head cover 4 so as to communicate with the hydraulic oil port 9 of the head cover 4,

Including a check valve 8 installed to open and close the flow path (7),

The flow path 7 is closed at the stroke end to secure the cushioning function, and the first thrust f1 pressurizes the cushioning ring 5 during the initial movement after the change of direction at the stroke end, and the flow path opened at the initial movement after the change of direction at the stroke end. The 2nd thrust force f2 which pressurizes the piston 2 by the hydraulic oil supplied through (7) can be ensured.

The check valve 8 described above,

A seating portion 10 extending from one end of the flow path 7 and having a check valve 8 installed thereon;

A body 12 fitted with the seating part 10 and having a through hole 11 communicating with the flow path 7;

Check ball 13 to open and close the through hole 11,

A pusher 14 for pressing and supporting the check ball 13,

An elastic member 15 (for example, a compressed coil spring is used) which biases the pusher 14 to elastically bias the initial state of closing the through hole 11 by the check ball 13,

And a plug 16 that is screwed to the seating portion 10 to support the elastic member 15.

At this time, to perform the cushion function at the stroke end, and during the initial movement after the change of direction at the stroke end is formed in the head cover (4) to increase the pressure area by pressing the cushioning (5) and the piston (2), respectively The configuration except for the flow passage 7 and the check valve 8 that opens and closes the flow passage 7 is substantially the same as the configuration of the hydraulic cylinder shown in FIG. Reference numerals are the same.

Hereinafter, with reference to the accompanying drawings an example of the use of the hydraulic cylinder with a built-in check valve according to an embodiment of the present invention will be described in detail.

As shown in FIG. 3, the flow path 7 formed in the head cover 4 at the stroke end is closed by the check valve 8. That is, since the flow path for draining the hydraulic fluid of the pressure chamber due to the movement of the piston 2 is gradually throttled by the cushioning ring 5, the speed of the piston 2 can be reduced to perform a cushioning function.

At this time, the check valve 8 for opening and closing the flow path 7 formed in the head cover 4 is kept closed. That is, as the pusher 14 presses the pusher 14 of the check valve 8 by the hydraulic fluid moving through the through hole 16a formed at the center of the plug 16 during the movement of the piston 2, the pusher 14 presses the pusher 14. By the check ball 13 to be cut off the through-hole 11 communicated with the flow path (7).

Therefore, the flow path 7 is blocked by the check valve 8 at the stroke end, thereby ensuring a cushioning function.

On the other hand, when the piston 2 starts to move by changing the direction at the stroke end (which means the fully extended or extracted state of the hydraulic cylinder), the check valve 8 is opened and the flow path 7 is maximized. Fully open. This causes the piston 2 to be pressurized by the hydraulic oil supplied through the oil passage 7 communicating with the hydraulic oil port 9.

That is, when the piston 2 starts initial movement after the change of direction at the stroke end, the first thrust force f1 for pressing the projection of the annular cushioning ring 5 is generated, and at the same time, the hydraulic oil supplied through the oil passage 7 The second thrust (pressing "f2" which presses the left end of the piston 2 in FIG. 3) by which the piston 2 is pressed is produced | generated by this.

As described above, when the piston 2 starts to move after the change of direction at the stroke end, the mutual frictional force between the head cover 4 and the cushioning ring 5 is reduced, and the cushioning ring 5 comes out of the stroke end. It is possible to sufficiently secure the hydraulic pressure areas for forming the thrusts f1 and f2.

Therefore, it is possible to prevent excessive pressure rise of the hydraulic pump for smooth initial operation of the hydraulic cylinder at the stroke end, and to prevent the sudden sudden operation of the hydraulic cylinder at the beginning.

1 (a) is a schematic view of a hydraulic cylinder according to the prior art,

Figure 1 (b) is a view showing a state in which the cushioning enters the head cover at the stroke end in the hydraulic cylinder of the prior art,

Figure 1 (c) is a view showing a time point when the initial operation in the opposite direction after the cushioning entry to the head cover is completed in the hydraulic cylinder of the prior art,

Figure 2 is a view showing a pressure profile (pressure profile) of the hydraulic cylinder cushioning device at the stroke end in the hydraulic cylinder according to the prior art,

3 is a schematic view of a hydraulic cylinder in which a check valve according to an embodiment of the present invention is incorporated.

* Explanation of symbols used in the main part of the drawing

One; Cylinder tube

2; piston

3; Cylinder rod

4; Head cover

4a; End cover

5; Cushioning

6; End cover

7; Euro

8; Check valve

9; Hydraulic oil port

10; Seating part

11; Through hole

12; Body

13; Checkball

14; Pusher

15; Elastic member

16; plug

Claims (2)

delete A cylindrical cylinder tube having an empty interior, a piston for partitioning a large chamber and a small chamber into the cylinder tube to maintain water pressure, a cylinder rod for linearly reciprocating the piston in the cylinder tube, and hydraulic oil from the cylinder tube. A head cover and an end cover fixed to both ends to prevent leakage of the cushion; a cushioning and cushion plunger respectively mounted to the outer side and one end of the cylinder rod to absorb mechanical shock at the stroke end; Including a flow path formed in the head cover to communicate with the hydraulic oil port of the head cover, and a check valve installed to open and close the flow path, At the stroke end, the flow path is closed to secure the cushioning function, and to the hydraulic fluid supplied through the first thrust for pressing the cushion ring during the initial movement after the change of direction at the stroke end and the flow path opened during the initial movement after the change of direction at the stroke end. In the hydraulic cylinder with a built-in check valve, characterized in that to secure the second thrust to pressurize the piston by: The check valve, A seating portion extending from one end of the flow path to which the check valve is installed, a body coupled to the seating portion and having a through hole communicating with the flow path, a check ball to open and close the through hole, and the check ball And a pusher for pressing the pusher, an elastic member elastically biased to an initial state by pressing the pusher to close the through hole by the check ball, and a plug screwed to the seating part to support the elastic member. Hydraulic cylinder with a built-in check valve, characterized in that.

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